1. Field of the Invention
This invention relates to an apparatus for winding a continuously oncoming film web onto successively deliverable winding tubes, including a rotatably drivable contact roller for delivering the film web in a feeding direction, and including the following, associated with the contact roller: a winding station for the winding tube for winding the film web into a coil; a winding preparation station for receiving a new winding tube, which upon a change of winding tubes replaces the winding tube wound with a coil of the film web in the winding station; a transverse-cutting device for cutting the film web crosswise in the region between the winding station and the winding preparation station; and upon a change of winding tubes, the winding tube bearing the coil can be removed from the winding station, the transverse-cutting device for cutting the film web crosswise can be transferred from a position of repose into a working position, and upon severing of the film web, a leading end of the trailing film web is formed, the formed leading end of the film web can be delivered to the new winding tube located in the winding preparation station and wound onto the new winding tube, and the new winding tube, after receiving the leading end of the film web, can be transferred from the winding preparation station into the winding station.
This invention also relates to a method for winding a continuously delivered film web onto successively delivered winding tubes into a coil and performing a change of winding tubes for replacing the winding tube, wound with a coil, with a winding tube having a winding apparatus with a contact roller, by which the film web is delivered and transferred to a winding tube rolling on the contact roller and wound up into a coil, and having a transverse-cutting device for the film web for severing the film web, forming a leading end of the trailing cut-off film web for application onto a new winding tube. A delivery device delivers a new winding tube, for replacing the winding tube wound with the coil when winding tubes are changed, wherein at the onset of the change of winding tubes, the new winding tube is placed on the contact roller, forming a contact gap, and the film web is severed either before passing through the contact gap or after passing the through the contact gap. The leading end of the film web formed upon severing of the film web is received by the new winding tube.
Such winding apparatuses are distinguished by the continuously delivered film web being continuously wound up into a coil, and once a predetermined coil diameter is reached, the transfer onward of the complete coil wound onto the winding tube and the delivery of a new winding tube to form a new coil from the film web are automated, without having to interrupt the continuous delivery of the film web.
2. Discussion of Related Art
A conventional winding apparatus is described for instance in German Patent Reference DE 42 13 712 C2 and European Patent Disclosure EP 12 47 773 A2, the disclosure contents of which are incorporated into this specification by reference.
The winding tubes are typically embodied of an electrically nonconductive material, such as cardboard, and are thrust onto a winding shaft, by which the winding tubes are moved and manipulated in the apparatus. Once the film web is wound up, the winding shaft is expelled from the winding tube, and the winding tube then forms the core of the wound-up coil of the film web.
Until now, during a change of winding tubes, the leading end of the trailing film web, created by the transverse-cutting device, is typically transferred onto the new winding tube, such as a cardboard tube disposed on a winding shaft, by providing the circumference of the winding tube with an adhesive, such as an adhesive strip, to which the leading end of the film web adheres on passing through the winding preparation station, thus being taken over by the new winding tube in the winding preparation station. Although this method is proven in practice, it cannot be done advantageously with all kinds of film webs, especially webs of plastic film, because adhesive residues unavoidably adhering to the film web can be disadvantageous in the later processing of the film web wound up to form the coil. Also, applying the adhesive, for instance in the form of adhesive strips, is undesirably complicated.
Various attempts have been made to accomplish the takeover of the leading end, formed during a change of winding tubes, of the film web without the aid of adhesive, which is known as adhesive-free prewinding.
From German Patent Reference DE 36 30 572 C2, it is known for the leading end of the film web, formed by the transverse-cutting device, to be delivered to the new winding tube with the support of suitably aimed blown air in compulsory fashion via a contact-pressure device, which surrounds the periphery of the new winding tube and has a revolving conveyor belt, causing the leading end of the film web to be taken on by the new winding tube. However, in practice a contact-pressure device with a revolving contact-pressure belt does not make it possible under all operating circumstances for the leading end to be received on the new winding tube in a satisfactory and reliable way, particularly above a certain feeding speed of the continuously delivered film web and above a certain thickness of the film web, this contact-pressure device is inadequate.
From European Patent Reference EP 12 47 773 A2, it is known for the leading end of the film web to be charged electrostatically and deflected by blown air onto a new winding shaft. However, in practice this does not always function in satisfactory fashion, because charging the film web is difficult, depending on the plastic used.
From U.S. Pat. No. 4,770,358, a winding apparatus is known which has a rotary arm with two winding tubes. The film web is wound into a coil on a winding tube. Once the winding tube with the coil is finished, the rotary arm is pivoted 180° and the film web is wound into a coil on the second winding tube located on the rotary arm. After the rotary arm is pivoted, the film web is severed by a transverse-cutting knife and blown onto the new winding tube by blown air, which is blown by a blower device onto the top side of the end of the film web, and by electrostatic charging. The winding tubes are connected to one another via the rotary arm and are moved and pivoted in common.